The present disclosure relates to an image processing device and an image display apparatus that correct an image to be displayed on a display to improve the reproducibility and fineness of the image.
Displays such as plasma displays and liquid crystal displays have been increasingly made larger in size and higher in definition, and have been used widely for TV sets, monitors of personal computers, etc. In such displays, sub-pixels for displaying key colors for color display are arranged on the plane. While the key colors emitted from the sub-pixels are separated from one another, they appear mixed since the sub-pixels are adjoining to one another, thereby permitting expression of neutral colors other than the key colors. These sub-pixels are previously allocated to designated compartments at the time of manufacturing the displays, and the arrangement thereof is also fixed at the time of manufacturing.
In displays having sub-pixels of the general three primary colors arranged in a striped shape, the sub-pixels in each pixel are often lined in RGB order. When red is present on the left and blue on the right next to red in an image displayed, only R sub-pixel is lit in the left-side pixel and only B sub-pixel is lit in the right-side pixel in pixel-by-pixel control. In this case, a total of four sub-pixels are present, not lit, between the R sub-pixel of the left-side pixel and the B sub-pixel of the right-side pixel. The portion of the image that can be displayed by four sub-pixels is equivalent to that of 1.3 pixels. Having such 1.3 pixel-equivalent sub-pixels being not lit means that a gap equivalent to 1.3 pixels is displayed as a black line.
There is conventionally known a character display apparatus that can display characters with high definition using a display device capable of color display (see Japanese Unexamined Patent Publication No. 2001-100725, for example). According to such a character display apparatus, jaggies at display of characters on a liquid crystal display are made inconspicuous by controlling sub-pixels individually, thereby permitting display of characters with high definition.
In the above conventional technique, which is specialized in character display, a gap still occurs in a color boundary portion between a red display region and a blue display region in the area other than portions involving characters and the background. In the arrangement of sub-pixels in RGB order from left, when red is on the left and blue on the right next to red on the screen, the gap of sub-pixels occurring in the color boundary portion is equivalent to 1.3 pixels. There is therefore the possibility that the gap may be visually recognized as if a black gap is present in the color boundary portion.
For the reason described above, there is a need for an image processing device that makes inconspicuous black lines occurring in color boundary portions of an image displayed on a display in which sub-pixels are arranged in a striped shape, to improve the reproducibility and fineness of the image.